Rainfall distribution on All India scale

Normal: percentage departure of realised rainfall is within ± 10 % of the Long Period Average
Below Normal: percentage departure of realised rainfall is < 10% of the Long Period Average
Above Normal: percentage departure of realised rainfall is > 10% of the Long Period Average
All India Drought Year: When the rainfall deficiency is more than 10% and when 20 to 40% of the country is under drought
conditions, then the year is termed as All India Drought Year
All India Severe Drought Year: When the rainfall deficiency is more than 10% and when the spatial coverage of drought is more than 40% it is called as All India Severe Drought Year